See bottom of table for explanation of headings. Note that visibility varies from site to site, and at different states of the tide on the same site. If visibility is low on a measured dive site, the chances are that it will be better at a different site (and vice-versa!). The potential outlook for diving over the next few days is given in good faith and without any guarantee!
Diving conditions and visibility recordings will start soon. Keep checking this page for updates
|Date||Time||Site||Viz (m)||Cloud /
Sun / Rain
hr +/- HW
Sea State / Swell /
Visibility is the depth to which a white disk (secchi disk) is visible from the surface, measured as the average of two readings - the depth to which it is lowered and just no longer visible, and the depth at which it reappears when raised. (Usually there is not too much difference between the two). A tilde indicates an approximate reading that is estimated rather than measured (eg: measured: 5, approx: ~5). Note that surface visibility is often different to visibility at depth. Cloud cover and the height of the sun (indicated by time of day, and/or the approximate angle of the sun in the sky) and sea state will also affect visibility. Cloud cover is measured in octas (8=8/8 = total cloud cover, 0=0/8 = clear sky). The state of the tide when the viz was measured is indicated as number of hours +/- HW Greenock and the approximate tidal cycle is indicated by the background: blue = Neaps, red = Springs, yellow = in between.